Improved method of securing artificial teeth to cast plates



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, Letters Patent Nb. 69,615, (lated October 8, 1807.

IMPROVBD METHOD OF SEGURING ARTIFICIAL TEETH T0 GAST PLATES..

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' Be it known that I, JAnnsl 1B. BEAN, of the city and county of Baltimore, and State ot' Maryland, have invented a new and improved Method of Securing Artificial Teeth to Cast Ilates; and I do hereby declare the following to be a full, clear, and exact description of thc same, suiiicient to enable those skilled in the art to which the invention appertains to make use of it, reference being had to the accompanying drawings', forming part of this specification, 4'in which,.- v A .Figure 1 represents a perspective view oi' my invention, a portion of the flask being-removed to show the interior constrnction'and arrangement ot' the apparatus.

Y Figure 2 is a perspective view of the plate with .tho teeth attachedV4 Figure 3 is a vertical cross-section of the plate and one of the teeth attached to it.

In this invention, apla'te cast of aluminum or other-similar meta-l is employed, having recesses into which the teeth are fitted. A groove is left behind the teeth, between them and the plate, into which the pins attached to' the teeth project when in place.' This groove, having pits or recesses Valong its sides, is afterwards filled with melted tin under pressure., the 'teeth being thus firmly secured to the plate.

In the'drawings, D represents the plate, upon which the teeth (Z ci are to be fixed. This plate is prepared, and the fas'tening'of .the teeth is effected in the following manner:

First, I cast a Yplateof aluminum, having around the line which the teeth are to cover a. recess or cavity, E E. This plate, with four' teeth removed to exhibit clearly its construction, islshown in iig. 2 of the drawings. It will be observed that the lower edge ofilthis recess terminates in a deep, sharp groove, e, in which the necks of the teeth'or thin edges ofthe artificial gums d Z are stopped and confined securely, beingr tted close against the plate on` alljsides. It will also be'observed that a groove', e e', at the upper part of the recess E E, along the line e e`extendsall around the plate between it and the teeth, into which the platinum pins of the teethblocks project. This groove has, along its sides, pits, holes, and recesses, cut ordrilled into the'thickcr portions of the plate, and also all rough andjagged points or under cuts that can be obtained. This groove is made so deep that when the teeth are all iitted to the plate the cavity' along'this line is not filled up, but an empty channel remains behind the teeth running along the line of the platinum pins the whole length of the line of l teeth from the point to the point i.

When the plate D has been constructed in lthis shape, thcteeth (Z d are inserted in their proper places in the recess E E, and secured by running a little melted wax along the line of juncture of the teeth `with the t plates, completely stopping up all crevices between and around the teeth lea-ding toward the groove c e behind the teeth. Two. small cylinders of wax, g g, close the two exits of the channel t" t, and project a short distance above the teeth.' The wholeis now ready to be placed in the investment of pumicest0nc and plaster for the permanent fastening of the teeth to the plate. This is effected in the'following manner:

First, I provide-myself` with a flask, A, of the form shown in the drawing, g. 1. This flask I fill about l one-third full of a composition of two parts, by weight, of powdered pumicesstonannd one partei calcined plaster of Paris mixed with water, and sutered to harden.

The plate D, having the teeth fixed to it as above described, is then placed upon the layer of composition nthe flask, the teeth projecting upward, and another similar portion of the same composition poured in, suili cient to coinpleteiyhcnvelop the plate andteeth, and leave the two little cylinders oi' wax, g g, projecting above. This layer ci' composition becoming hardened, the wax cylinders projecting above it are melted down even with the surface by means of a het instrument. Two stout brass tubes, B B, of a funnel 'form are placed with their small ends-downward, o nc over each oil'thc wax cylinders g g, and,l being warmed, they embed themselves in the wax. Athird portion ofthe composition above described is now poured in, filling up the flask to near the top of the brass tubes. The two high 'conduits C C, of cast iron or other suitable material, about live inches in length, are made to fit into the conical cavities of the brass tubes fixed into thc flask by means of a close-tting ground joint, 'but so as to be easily'put in or'removcd. The flask is now dried by a gentle heat, and heated to about the melting point of tin. The wax being melted is cntirelyabsorbed from around the teeth by the surrounding composition. The wax cylinders gg'likewise disappear', and an open channel now remains, running from the bottom of one tube, B, around back of the teeth, connecting with all the minute interstiees between and behind the teeth, to the bottom of the tube B, over the other extremity ofthe plate. The brass tubes B B are now exposed to the heat, so as to be somewhat above the temperature of the remainder of the fiask, and the conduits C C are heated almost to redness` and dropped into their places in B B, fig. 1. Pure tin, heated to about the temperature at which olive oil takes fire, is now poured into one of the conduits. The metal thus poured into the conduit flows down through the empty channel c c,.and up into the other conduit. The first conduit is kept full, and as soon as the metal appears in the second, it also is filled to the top by pouring the' metal into it. As soou as both conduits are full, a Wet cloth is applied to the outside of the flask A, so as to cool its contents first, while the pressure is kept up by the iiuid metal in the conduits. If the met-al in the conduits were first cooled, that in the groove e e would all be drawn out to supply the deficiency caused by the shrinking, while, by cooling the groove first, the final shrinkage takes place in the conduits, and we find the metal has been forced into every minute pore and crevice between and around the teeth and platinum pins, and into the pits, under cuts, and retaining points along the channel e c, thereby most elfectually securing the teeth to the plate. As soon as the whole apparatus has suiiiciently cooled, the composition is carefully removed from around the teeth, the plate, with the conduits attached, removed from the flask, and the gates cut off at the bottom ofthe brass tubes B B. The brass tubes can non be removed from the conduits, and the metal melted out of the latter.

I have been for a long time experimenting with this process, and can say that with anything like reasonable care iu conforming to the directions above given, the success ofthe operation will be uniform and perfect. The teeth thus fastened to the plate are attached as perfectly as if they were a part of the metallic plate itself, and tho work is more easily repaired-than any other kind in use. Should the teeth become injured or broken, they may be removed from the plate, and by supplying the broken portion with a new block from the same mould, and repeating the operation above described, it is rendered as perfect as before the injury. The same process can also be used for securing the teeth to lower sets cast in solid gold or silver, thereby securing weight in a lower set, which is as great a desideratum as lightness is in an upper set.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The dental plate, cast of aluminum or other similar metal, having the recesses E E and the channel e c, behind the teeth when they are in position, substantially as described.

2. I claim the process, above described, offercing melted tin or other metal around the teeth and platinum pins, as and for the purpose specified.

3. I claim the use of melted tin for the purpose of filling the channel or cavity c c, and attaching the teeth having platinum pins, as for vulcanite work, to a metallic plate, as and for the purpose herein shown and described.

JAS. B. BEAN` Witnesses:

J AMES H. GRIDLEY, Seton C. Kaitos. 

